Halftone is a reprographic technique that simulates continuous tone images. Halftoning algorithms can be used to create a binary representation of a continuous tone image. Different types of printers have utilized different types of halftone methodologies that are a good fit to the printer technology.
For example, inkjet printing mechanisms use moveable cartridges, also called pens, that use one or more printheads formed with very small nozzles through which drops of liquid ink (e.g., dissolved colorants or pigments dispersed in a solvent) are fired. To print an image, the carriage traverses over the surface of the print medium, and the ink ejection elements associated with the nozzles are controlled to eject drops of ink at appropriate times pursuant to command of a microcomputer or other controller. The pattern of pixels on the print media resulting from the firing of ink drops results in the printed image.
In inkjet printers, halftone imaging is typically accomplished using error diffusion, blue noise or other halftone algorithms that require limited or no dot size variations.